Translation:

4. Allah has not made for any man two hearts in his (one) body: nor has He made your wives whom ye divorce by Zihar your mothers: nor has He made your adopted sons your sons. Such is (only) your (manner of) speech by your mouths. But Allah tells (you) the Truth and He shows the (right) Way.

Notes (Tafseer)

3669. "Two hearts in his (one) breast": two inconsistent attitudes: such as serving Allah and Mammon; or subscribing to both Truth and Superstition; or hypocritically pretending one thing and intending another. Such a thing is against Allah's Law and Will. Apart from the condemnation of general hypocrisy, two pagan customs of the Times of Ignorance are mentioned, and their iniquity pointed out. See the notes 3670 and 3671.

3670. This was an evil Arab custom. He pronounced words importing that she was like his mother. See also lviii. 1-5. where this is condemned in the strongest terms and punishment is provided for it. A man sometimes said such words in a fit of anger; they did not affect him, but they degraded her position.

3671. If a man called another's son "his son", it might create complications with natural and normal relationships if taken too literally. It is pointed out that it is only a facon de parler in men's mouths, and should not be taken literally. The truth is the truth and cannot be altered by men's adopting "sons". "Adoption" in the technical sense is not allowed in Muslim Law. Those who have been "wives of your sons proceeding from your loins" are within the Prohibited Degrees of marriage; iv. 23: but this does not apply to "adopted" sons.