The Meaning of the Condition in the Story of the Manumission of Barirah

What is the interpretation of the saying of the Prophet (peace and blessings be upon him) to 'A'ishah in the hadith of Barirah: (Take her and stipulate the patronage for them), when he said at the end of the hadith: (Indeed, every condition that is not in the Book of Allah is invalid), even though he ordered her to stipulate it with them?

The explanation of this statement: Some of them said: The (lam) here means (upon), meaning: stipulate upon them,As in the saying of Allah the Exalted: [Surat al-Ra'd: 25] meaning: upon them is the curse, but this interpretation is invalid; because she did stipulate the patronage with them and they did not accept it,And the correct view is: that the meaning is stipulate for them, meaning: agree with them on this condition. The Messenger of Allah (peace and blessings be upon him) only ordered her to agree to the condition to make it clear that even if it is stipulated, it is invalid, so that its invalidity is made clear after it has been stipulated, and this is more eloquent. Its parallel is that he ordered the one who prays poorly to pray, even though he does not settle in his prayer, but he intended to make it clear that an invalid prayer does not suffice even if a person performs it. This is the correct view.