i want to ask regarding naming a son Umair.its a quite common name and name of a sahabi as well but one famous mufti his name is zarwali khan argues that umair means short life and a person who will be named umair will not live for more than 40 years so we are now confused and those who have already had a name umair are also worried .
In the Name of Allah, the Most Gracious, the Most Merciful.
Assalāmu ῾alaykum wa Rahmatullāhi Wabarakātu
The name Umair is suitable.
It being a diminutive (tasgheer) of Umar meaning small life does not necessarily mean that such a person will have a short life. Actually every one of us have short lives in comparison to the life of the hereafter. 
The name Umair is thus a form of reminding one of the short lifespan of this world and jolts him to prepare for life after death.Futhermore, every person’s lifespan is decreed while one is in the womb of his mother and even before coming into this world. See the following hadith:
حدثنا أبو بكر بن أبي شيبة حدثنا أبو معاوية ووكيع ح وحدثنا محمد بن عبد الله بن نمير الهمداني واللفظ له حدثنا أبي وأبو معاوية ووكيع قالوا حدثنا الأعمش عن زيد بن وهب عن عبد الله قال حدثنا رسول الله صلى الله عليه وسلم وهو الصادق المصدوق إن أحدكم يجمع خلقه في بطن أمه أربعين يوما ثم يكون في ذلك علقة مثل ذلك ثم يكون في ذلك مضغة مثل ذلك ثم يرسل الملك فينفخ فيه الروح ويؤمر بأربع كلمات بكتب رزقه وأجله وعمله وشقي أو سعيد
Abdullah (b. Mas’ud) reported that Allah’s Messenger (ﷺ) who is the most truthful (of the human beings) and his being truthful (is a fact) said:
Verily your creation is on this wise. The constituents of one of you are collected for forty days in his mother’s womb in the form of blood, after which it becomes a clot of blood in another period of forty days. Then it becomes a lump of flesh and forty days later Allah sends His angel to it with instructions concerning four things, so the angel writes down his livelihood, his death, his deeds, his fortune and misfortune. (Sahih Muslim: vol 8, hadith 2643, darul fawaa’id)
And Allāh Ta῾āla Knows Best
Student Dārul Iftā
Checked and Approved by:
Mufti Ebrahim Desai
مصباح الالغات:567(,دار الاشاعات) (a)