A buyer stipulating the wala: Abu Hanifah said this purchase is invalid and not allowed

It is narrated from Sayyiduna Ammar (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said: "In dry ablution (tayammum) there is one strike, for the face and for the palms."

It is narrated from Sayyiduna Abu Hurayrah (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) urinated, then he (peace and blessings be upon him) struck his blessed hand on the ground and wiped his face and hands with it.

Ibn Abza narrates from his father that Sayyiduna Umar (may Allah be pleased with him) said to Sayyiduna Ammar (may Allah be pleased with him): "Do you remember the day when we were at such and such a place and we became ritually impure (junub)? We did not find water, so we rolled about in the dust. Then, when we came to the Prophet (peace and blessings be upon him), we mentioned this before him, and he (peace and blessings be upon him) said: 'This would have been enough for you both.'" (Saying this) the narrator al-A'mash struck his two hands once (on the earth), then blew on them, then wiped his face and palms with them. It is mentioned that the view of (Imam) Abu Hanifah is: There are two strikes; one strike does not suffice.