Resting only the tip of the nose on the floor during Sujood

Source: The Prophet’s Prayer by Shaikh al-Albani

The Prophet (Salla-Allaahu alaihi wa sallam) said: “I am commanded to prostrate on seven bones: the forehead (along with the tip of the nose), the two hands [in another version palms], the two knees, and the toes of both feet.” [Al-Bukhari and Muslim]. When he (Salla-Allaahu alaihi wa sallam) said the forehead, he indicated by moving his hand around his nose.

He (Salla-Allaahu alaihi wa sallam) also used to say, “When a slave prostrates, seven limbs prostrate with him; his face, his palms, his knees and his feet.” [Muslim]

He (Salla-Allaahu alaihi wa sallam) also used to say, “There is no prayer for the one whose nose does not feel as much of the ground as the forehead.” [Darqutni, Tabarani and authenticated by al-Albani]

Applying the above command necessitates resting the forehead and the nose on the ground during Sujood.