The plural of world
الْحَمْدُ للّهِ رَبِّ الْعَالَمِينَ [2]
The Praise is for Allah the Lord of the Worlds [1:2]
في اصول الكافي باسناده إلى أبى عبد الله عليه السلام قال: من قال أربع مرات إذا اصبح: ” الحمدلله رب العالمين ” فقد ادى شكر يومه، ومن قالها إذا امسى فقد ادى شكر ليلته
In Usool Al-Kafi by his chain up to –
Abu Abdullah-asws having said: ‘The one who recites [1:2] ‘الْحَمْدُ للّهِ رَبِّ الْعَالَمِينَ’ four times every morning, has given his thanks for his day, and one who says it in the evening has given his thanks for his night’.[1]
[1] Tafseer Noor Al Saqalayn – CH 1 – H 63