The worshipper should be unhurried and at ease in every essential part of the prayer, because being unhurried and at ease is also an essential part of prayer. So he should be unhurried and at ease when standing, when bowing, when prostrating, when rising from bowing, and when sitting between the two prostrations. Being unhurried and at ease means allowing the limbs to settle into the posture that one is doing. Hence when Hudhayfah ibn al-Yaman (may Allah be pleased with him) saw a man not bowing and prostrating completely, and not doing either in an unhurried manner, he said to him: You have not prayed! With this shortcoming, your prayer does not count, and if you die, you will die following something other than the Sunnah of Muhammad (blessings and peace of Allah be upon him). What is meant by the Sunnah here is the way. This applies to both obligatory and supererogatory prayers, because the Prophet (blessings and peace of Allah be upon him) used to move unhurriedly when bowing and prostrating, and in all the essential parts of the prayer. So if you die doing something other than that, you will be going against the Sunnah of the Prophet (blessings and peace of Allah be upon him) and his way in prayer. This is an example of the Sahabah teaching the Tabi‘in, and transmitting the Sunnahs and rulings to those who came after them. It is also an example of their keenness to teach people as the Prophet (blessings and peace of Allah be upon him) had been keen to teach them..