Who was the first to establish the practice of two rak'ahs before being killed?

The first person to establish the tradition of praying two units (rak'ahs) before being executed was the esteemed Companion Khubayb ibn Adi (may Allah be pleased with him). When the disbelievers brought him out to kill him during the time of the Prophet (peace and blessings be upon him), he asked them to allow him to pray two rak'ahs, thus being the first to do so.