Is it compulsory for us to go out and look for the new moon of Ramadaan?
:باسم الله والحمد لله والصلاة والسلام على رسول الله وعلى آله وصحبه أجمعين
I have not come across any narration which commands us to go out and look for the new moon (hilaal) of Ramadaan in the form of the act being obligatory.
However we do have narrations that allude to the practice being something recommended via what the scholars of jurisprudence methodology (Usool alFiqh) call ‘the required meaning’ or دلالة الاقتضاء
A narration which would provide the ruling of this practice being something recommended via the above mentioned ‘Usool alFiqh’ process, would be the narration of Abdullah bin Umar (May Allah be pleased with him) in which he says:
The people searched for the moon, so I informed the Messenger of Allah (peace, salutations & blessings be upon him) that I had sighted it. He (then) fasted and commanded the people to fast (as well).
(Recorded by Imam Abu Dawood in his book of compiled hadeeth called Sunan Abi dawood).
The portion of the narration which tells us that the companions searched for the moon is the focal point of the study through which the ruling of this practice being recommended has been concluded. Our scholars relay to us that the ‘required meaning’ from the narration in this form teaches us that it is recommended to go out and search for the new moon which marks the beginning of Ramadaan.
And Allah knows best.