Masruq said: I came to greet Sayyidah Aishah (may Allah be pleased with her) with salam, and I accompanied Abdullah bin Mas'ud (may Allah be pleased with him) until he began the tawaf. He did three circuits with ramal and four walking, then he prayed two rak'ahs behind the Station, then went to the Black Stone and kissed it, then set out towards Safa, stood on the edge of Safa and recited the talbiyah. I said: I have been forbidden from the talbiyah. He said: I command you to do it; the talbiyah was an answered response, the one made by Ibrahim. When he came down into the valley, he ran (sa'y) and said: "Allahumma ighfir warham wa anta al-a'azzu al-akram" (O Allah! Forgive and have mercy, and You are the Most Mighty, the Most Generous).
This is the most authentic of the narrations from Ibn Mas'ud on this matter.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 9351