وَٱلْفُرْقَانِ ۚ فَمَن شَهِدَ مِنكُمُ ٱلشَّهْرَ فَلْيَصُمْهُ ۖ وَمَن كَانَ مَرِيضًا أَوْ عَلَىٰ سَفَرٍ فَعِدَّةٌ مِّنْ أَيَّامٍ أُخَرَ ۗ يُرِيدُ ٱللَّهُ بِكُمُ ٱلْيُسْرَ وَلَا يُرِيدُ بِكُمُ ٱلْعُسْرَ وَلِتُكْمِلُوا۟ ٱلْعِدَّةَ وَلِتُكَبِّرُوا۟ ٱللَّهَ عَلَىٰ مَا هَدَىٰكُمْ وَلَعَلَّكُمْ تَشْكُرُونَ
The month of Ramazan[is that] in which was revealed the Qur’an, a guidance for the people and clear proofs of guidance and criterion. So whoever sights [the new moon of] the month, let him fast it; and whoever is ill or on a journey – then an equal number of other days. Allah intends for you ease and does not intend for you hardship and [wants] for you to complete the period and to glorify Allah for that [to] which He has guided you; and perhaps you will be grateful.
Surah Baqarah Ayat 185.

Hz. Talha ibn Ubayd ^Rz reported: Whenever the Messenger of Allah ^PBUH, saw the crescent moon, he would say:
اللَّهُمَّ أَهْلِلْهُ عَلَيْنَا بِالْيُمْنِ وَالْإِيمَانِ وَالسَّلَامَةِ وَالْإِسْلَامِ رَبِّي وَرَبُّكَ اللَّهُ
O Allah, bring it over us with blessings and faith, safety and Islam. My Lord and your Lord is Allah.
Source: Sunan al-Tirmidhī 345

During the stay of Hazrat Imam Mahdi ^PBUH at the city of Nahrvala [Patan Sharif in Gujarat], Hazrat Bandagi Miran Syed Mahmood ^Rz.. asked the Imam Alaihissalam, “Miranji! a person is a seeker of Allah from his childhood and another person gives up the world [performs the Tark-e-Dunya] after earning [by his efforts]. What is the difference between these two persons?” The Imam ^PBUH said, “There is great difference between them, like that between the earth and the sky!” The Imam ^PBUH further said, “The person who earns a livelihood and gives up the wealth becomes entitled to more [divine] rewards than what he leaves when he gives up the world and becomes the seeker of Allah. And this is afzal [more excellent].

Ameer-Ul-Muminin Hazrath Ali -ul Murtuza ^Rz.said that:”To keep silent when you can say something wise and useful is as bad as keeping on propagating foolish and unwise thoughts.”