What is the authenticity of the phrase: "Whoever is saved among us on the Day of Resurrection will take his brother by the hand"? Is it permissible to recommend it to people of piety so that they may remember us on the Day of Resurrection? And does this intercession benefit on the Day of Resurrection or after entering Paradise?

We do not know who coined the phrase "A survivor taking his brother by the hand." However, we have not found any evidence for its specific meaning concerning a survivor taking his brother by the hand, except for a weak hadith (definition) narrated by Anas. As for the general meaning, which is the intercession of the righteous, it is sound and established, but with conditions: Allah's pleasure with both the intercessor and the one interceded for, and His permission for the intercession. A believer's heart is attached to Allah Almighty, for all matters are in His hand. Intercession will take place by His permission, Glorified be He, in the plains of the Day of Judgment and after entering Paradise.