The scholars (may Allah have mercy on them) differed concerning voluntary prayers after dawn has broken and before the Fajr prayer. The Hanbali view is that it is not allowed, except for the Sunnah prayer of Fajr only. 

It says in Daqaa’iq Ooli an-Nuha, 1/272: There are five times when prayer is not allowed, one of which is from the break of dawn until sunrise. End quote. 

What is meant is that once dawn has broken, one should offer the two rak‘ahs of Fajr, then refrain from praying, because of the report narrated by Abu Dawood (1278) from Yasaar, the freed slave of Ibn ‘Umar, who said: Ibn ‘Umar saw me when I was praying after the break of dawn, and he said: O Yasaar, the Messenger of Allah (blessings and peace of Allah be upon him) came out to us when we were offering this prayer and said: “Let those of you who are present convey it to those of you who are absent: do not pray anything after dawn except two rak‘ahs.” The hadeeth was classed as saheeh by al-Albaani (may Allah have mercy on him) in Saheeh Abi Dawood. 

In their view, this is based on the fact that the prohibition has to do with the time – which is the break of dawn, not with the act of prayer. There is another report from Ahmad, which is also the view of the Shaafa‘is, that the prohibition has to do with the act of prayer; hence, once one has prayed Fajr, one should refrain from praying, because of the report narrated by Abu Sa‘eed, according to which the Prophet (blessings and peace of Allah be upon him) said: “There is no prayer after ‘Asr prayer until the sun sets, and there is no prayer after Fajr prayer until the sun rises.” Narrated by Muslim, 827. According to the hadeeth of ‘Amr ibn ‘Abasah he said: “Pray Fajr, then refrain from praying until the sun rises.” Narrated by Muslim, 823. What this means is that the time when prayer is not allowed begins when one has prayed Fajr, not when dawn breaks. 

See: al-Majmoo‘, 4/76; al-Mughni, 1/428; al-Mawsoo‘ah al-Fiqhiyyah, 7/183 

Shaykh Ibn ‘Uthaymeen (may Allah have mercy on him) thought that this opinion was more likely to be correct, so from after Fajr prayer until sunrise is the time when prayer is not allowed. But before Fajr prayer there is no time when prayer is not allowed, but it is not prescribed to do anything at that time except offer the two (Sunnah) rak‘ahs of Fajr, because this is what was narrated from the Prophet (blessings and peace of Allah be upon him) and there is no report to suggest that he offered any voluntary prayer other than that. 

Shaykh Ibn ‘Uthaymeen (may Allah have mercy on him) said: But the correct view is that the prohibition has to do with Fajr prayer itself. As for the time between the adhaan and iqaamah, it is not included in the prohibition, however it is not prescribed to offer anything in that time apart from the two (Sunnah) rak‘ahs of Fajr. If this is the correct view, then what is the response concerning the hadeeth that is quoted as evidence by the author? 

The response to that notes two things: 

1.That the hadeeth is da‘eef (weak)

2.|Even if we assume that the hadeeth is saheeh, the words “There is no prayer after the break of dawn” may be understood as meaning that it is not prescribed for a person to offer any naafil or voluntary prayer other than the two (Sunnah) rak‘ahs of Fajr after the break of dawn, and that is true, because it is not appropriate for  a person, after the break of dawn, to offer any voluntary prayer except the two Sunnah rak‘ahs of Fajr. So if you enter the mosque and pray the two (Sunnah) rak‘ahs of Fajr, and the time for the (fard) prayer has not yet come, and you say, I shall offer a naafil prayer, we would say to you: Do not do that, because this is not prescribed; but if you were to do it, you would not be sinning. Rather we say that it is not prescribed, because the Messenger (blessings and peace of Allah be upon him) only prayed two brief rak‘ahs after the break of dawn, and that is the Sunnah of Fajr prayer only. Moreover, even making the two rak‘ahs lengthy is not prescribed.

End quote  from ash-Sharh al-Mumti‘, 4/51 

Shaykh al-Albaani (may Allah have mercy on him) said: 

Note: al-Bayhaqi narrated with a saheeh isnaad from Sa‘eed ibn al-Musayyab that he saw a man praying more than two rak‘ahs after dawn broke, bowing and prostrating a great deal, and he told him not to do that. The man said: O Abu Muhammad, will Allah punish me for praying? He said: No, but He will punish you for going against the Sunnah. This is an example of the brilliant answers of Sa‘eed ibn al-Musayyab (may Allah have mercy on him), and it is a powerful weapon against the innovators who think many innovations are good on the grounds that they are dhikr (remembrance of Allah) and prayer, then they criticize Ahl as-Sunnah for criticising their actions and accuse them of forbidding dhikr and prayer!, When in fact they are only criticizing their going against the Sunnah with regard to dhikr and prayer and so on.

End quote from Irwa’ al-Ghaleel, 2/236.

 And Allah knows best.