Al-Imaam Al-Bukhaaree, may Allaah bestow mercy on him, said: Ibraaheem bn Moosa narrated to us, he said Hishaam informed us from Ibn Jurayj who said UbayduLlaah bn Umar told me from Naafi from Umar bn al-Khataab, may Allaah be pleased with him, that Umar allotted for the Early Emigrants among the Companions four thousand (deenar) but allotted three thousand five hundred to his son, Abdullah. He was told, 'Is he not among the Emigrants, why did you reduce his share from four thousand?' Umar said, 'He was only brought along on Hijrah by his father; he cannot be compared with those who migrated on their own volition.' [7/253].
The author of Bahjahtun-Naadhireen [p. 655] said:
Lessons from the Hadith:
1. The sense of carefulness of Umar; this is called al-Wara.
2. The excellence of Early Emigrants [al-Muhaajiroon al-Awwaloon], those who migrated on their own volition, over others.
3. It is permissible for the ruler of a Muslim country (or community) to
allot some money to the people of faith so as to assist them in their
living. That gesture can also be extended to a person who has resigned
himself to Da'wah and knowledge acquisition.
Written: The first day of Rajab, 1433 [20th May, 2012].