"Salamun ‘ala nuhin fil ‘alamin" (Peace be upon Noah among the worlds).
In early mystical texts (e.g., Sulami’s Haqa’iq al-tafsir ), the 7 recitations of al-Salam during night prayers were believed to protect the believer from the 7 gates of Hell mentioned in Q 15:44. Each "salam" closes one gate. 7 salam