Nafi' (may Allah have mercy on him) said that Sayyiduna Ibn Umar (may Allah be pleased with him) used to perform ramal in the first three rounds and walk the (other) four, and he would say that the Prophet (peace and blessings be upon him) used to do the same.
(Ubaydullah said:) I said to Nafi': Did he walk between the two Corners? He said: He walked only because it made touching it easier.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 9269
Sayyiduna Abdullah bin Umar (may Allah be pleased with him) said that the Prophet (peace and blessings be upon him) ran three rounds and walked four, in Hajj and in Umrah.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 9270
Nafi' (may Allah have mercy on him) said that whenever Sayyiduna Abdullah bin Umar (may Allah be pleased with him) arrived for Hajj or Umrah, he would walk briskly for three rounds and slowly for four, and he would say that the Prophet (peace and blessings be upon him) used to do the same.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 9271