Minimum duration required for ruku and sujud

A man from Madinah narrates that the daughter of Hazrat Sa’d used to make an unusual effort to bend excessively in ruku. Hazrat Sa’d said to her that it is sufficient for you to place your hands on your knees.

Hazrat Ibn Masood says that when a person places his hands on his knees in bowing (ruku) and his forehead on the ground in prostration (sajdah), then these pillars (of prayer) have been fulfilled.

Hazrat Muhammad bin Ali (may Allah be pleased with him) says that placing your hands on your knees in bowing (ruku) and placing your forehead on the ground in prostration (sajdah) means that these pillars have been fulfilled.

Hazrat Ibn Umar (may Allah be pleased with them both) narrates that when a person places his forehead on the ground, that is sufficient.

Hazrat Ibn Sirin says that if one places his hands on his knees in bowing (ruku) and his forehead on the ground in prostration (sajdah), then these pillars have been fulfilled.

Hazrat Tawus, Hazrat Ikrimah, and Hazrat Ata say that when the forehead is placed on the ground, the obligation is fulfilled.

Hazrat Musayyib bin Rafi' says that when the forehead is placed on the ground, the obligation is fulfilled.

Hazrat Ma'qil bin Ubaidullah narrates that I asked Hazrat Ata about the minimum requirement for ruku and sujood, so he replied that when the forehead is placed on the ground and the hands are placed on the knees, then these pillars have been fulfilled.

Hazrat Mujahid says that when the hands are placed on the knees, then the ruku has been performed.