Imam Abu Bakr (may Allah have mercy on him) says that the hadith of Sayyiduna Ibn Abbas (may Allah be pleased with them both) is that the Prophet Muhammad (peace and blessings be upon him) said: "Indeed, I have been commanded to perform ablution when I stand for prayer." (That is, in situations other than those mentioned, performing ablution is not obligatory.)

It is narrated from Sayyiduna Abu Sa'id (may Allah be pleased with him) that the Prophet Muhammad (peace and blessings be upon him) said: "When any one of you comes to his wife (has intercourse with her) and then intends to do so again, he should perform ablution." This is the narration of San‘ani. The rest of the narrators, when narrating from Abu Mutawakkil, have mentioned «‏‏‏‏ عن» ‏‏‏‏ instead of «‏‏‏‏‏‏‏‏سمعت» ‏‏‏‏.