It is narrated from Muhammad bin Yahya, he says: I asked Abdullah bin Abdullah bin Umar, "From whom is it narrated that Ibn Umar (may Allah be pleased with them both) used to perform ablution for every prayer, whether he was in a state of purity or impurity (with or without ablution)?" He replied: Asma bint Zaid bin Khattab informed him that Abdullah bin Hanzalah bin Abi Amir narrated to her that the Messenger of Allah (peace and blessings be upon him) was commanded to perform ablution for every prayer, whether he was in a state of purity or impurity. Then, when this became burdensome for him, he was commanded to use the miswak for every prayer instead. Therefore, Ibn Umar (may Allah be pleased with them both) thought that he had the strength to perform a new ablution for every prayer, so he would not leave performing a new ablution for every prayer.