Vowing to spend a percentage of his salary on building Masjids and publishing books

Q: Once I joined my work three months ago, I made a vow that if I succeeded in my work I would give away 500 Riyals for the sake of Allah every month from the salary for ten months, starting from the third month. I had the intention to spend such money on construction of Masjids (mosques) or printing and distributing some useful books in my homeland, Egypt. Is it permissible for me to delay fulfilling my vow until I return to my homeland after finishing my residence in Saudi Arabia? If it is permissible to delay it, can I spend such money on other channels? I want to invite my wife to live with me in the Kingdom of Saudi Arabia, and this requires that I look for a flat and provide the furniture; however, I still keep my vow to spend the whole sum of money through the specified channels upon my return to Egypt. Moreover, it is difficult to trust anybody to send the money with to spend on my behalf through the intended channels, and I want to make sure of that. Is it permissible to send that money to my parents? My mother wants to perform Hajj (pilgrimage) and my father needs to settle some of his debts. It should be noted that my salary is 2000 Riyals a month.

A: It is obligatory on you to fulfill the vow you made according to your intention, because it is (Part No. 23; Page No. 294) a vow to do an act of obedience. It was authentically reported that the Prophet (peace be upon him) said, Whoever vows to obey Allah should obey Him. Also, the Prophet (peace be upon him) said, The reward of deeds depends upon the intentions and every person will get the reward according to what he has intended. May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.