What are the teachings of Prophet Muhammad (saw) on stipulating conditions that are not present in Allah's Laws?
 Narrated 'Aishah (ra) that Barira came to seek her help writing of emancipation and she had to pay five Uqiya (of gold) by five yearly installments. 'Aishah said to her, "Do you think that if I pay the whole sum at once, your masters will sell you to me, and I will free you and your Wala' will be for me." Barira went to her masters and told them about that offer. They said that they would not agree to it unless her Wala' would be for them. 'Aishah further said, "I went to Allah's Messenger () and told him about it." Allah Messenger () said to her, "Buy Barira and manumit her and the Wala' will be for the liberator." Allah's Messenger () then got up and said, "What about those people who stipulate conditions that are not present in Allah's Laws? If anybody stipulates a condition which is not in Allah's  Laws, then what he stipulates is invalid. Allah's Condition (Laws) are the truth and are more solid."