To what extent is the statement true that the six or seven "Verses of Tranquility" bring tranquility to their reciter, and where are these verses found in the Holy Qur'an?

There is no divinely revealed text that specifies a particular promise for reciting the verses of tranquility (Ayat al-Sakinah). However, it is narrated that Ibn al-Qayyim, along with his teacher Ibn Taymiyyah, experienced reading the verses of tranquility during times of hardship and heart distress. It is mentioned that Allah sent down tranquility upon His Messenger and the believers in situations of anxiety and turmoil. Allah mentioned tranquility in His Book in six instances: in the story of the Ark (Tabut), upon the Messenger and the believers, upon Abu Bakr in the cave, in the hearts of the believers so they might increase in faith, upon the believers during the Pledge of the Tree (Bay'at al-Shajarah), and upon the Messenger and the believers when the disbelievers harbored the fervor of ignorance in their hearts.