My friend had made a vow to Allah Ta'ala on a certain issue.

Answer

He displays a trait of nifaaq (hypocrisy). Violating a pledge/vow made with Allah Ta'ala is a sin of an exceptionally serious nature. Your friend comes within the scope of the Qur'aanic aayat:

"And from people there are some who pledged with Allah: 'If He gives us of His grace (wealth), then most assuredly we shall give

Sadqah and most certainly we shall become pious.

Then when He bestowed to them from His grace, they became niggardly (stingy).

They turned away whilst ignoring (their pledge).

Then (as a consequence) He

(Allah) instilled nifaaq in their hearts until the day they will meet Him because they had violated what they had pledged to Him, and because they spoke lies." (At-Taubah, 75,76, and 77)

Tha'labah Ibn Haatib Ansaari requested Rasulullah (Sallallahu alayhi wasallam) to make dua so that he (Tha'labah) becomes wealthy. Rasulullah (Sallallahu alayhi wasallam) asked: "Are you not pleased with my way? I take oath by That Being in Whose power is my life! If I had desired, the mountains of Madinah would become gold. But I do not love such wealth." Tha'labah went away. After some time he came again, and repeated his request for wealth. In addition he pledged to fulfil the rights of all people. Then Rasulullah (Sallallahu alayhi wasallam) made dua for him. As a result of this dua, his goats increased considerably. Due to the huge flocks of goats he went to live on the outskirts of Madinah. He would come to perform Zuhr and Asr in Madinah with Rasulullah (Sallallahu alayhi wasallam).

His flocks went on increasing so much that he acquired a farm very far from Madinah Now he would come only on Jumuah to Madinah for Salaat. His flocks went on increasing so much that he felt constrained to settle very far from Madinah. He was now completely deprived of Jumuah and Jamaa't Salaat. After some time Rasulullah (Sallallahu alayhi wasallam) asked the people about Th'alabah. They said that due to his vast flocks of goats he was compelled to move very far from Madinah. Rasulullah (Sallallahu alayhi wasallam) then said thrice: "Woe to Tha'labah!"

Coincidentally, the Qur'aanic verses pertaining to Sadqah were revealed during this period. Rasulullah (Sallallahu alayhi wasallam) had the laws of Sadqaat on animals written. He appointed two persons to collect Sadqah on animals. He instructed them to go also to Tha'labah to collect the Sadqah due on his animals.

When they met Tha'labah and informed him of their mission, he asked to see the document detailing the Sadqah. While examining it, he commented: "This is a kind of jizyah which should not be taken from Muslims. For the present, you may leave. I shall later decide on this issue." (Jizyah is a tax levied on the non-Muslim citizens in an Islamic state.) Then the aforementioned Qur'aanic Verses were revealed. A relative of Tha'labah hastened to inform him of what had transpired. Tha'labah came to Madinah and requested Rasulullah (sallallahu alayhi wasallam) to accept his Sadqah. Rasulullah

(sallallahu alayhi wasallam) said that Allah Ta'ala has forbidden acceptance of his Sadqah. Tha'labah departed. A few days thereafter, Rasulullah (sallallahu alayhi wasallam) passed away.

Tha'labah then came to Hadhrat Abu Bakr Siddique (Radhiyallahu anhu) and offered his Sadqaat. He refused to accept Tha'laba's Sadqaaat. During the Khilaafat of Hadhrat Umar (Radhiyallahu anhu), he offered to give the Sadqaat. Hadhrat

Umar (Radhiyallahu anhu) too refused to accept it. Then when Hadhrat Uthmaan (Radhiyallahu anhu) became the Khalifah, Tha'labah requested him to accept his Sadqaat, but Hadhrat Uthmaa (Radhiyallahu anhu) also refused. Tha'labah died during the Khilaafat of Hadhrat Uthmaan (Radhiyallahu anhu) without his Sadqaat having been accepted.

This is the status of your friend who has violated his pledge with Allah Ta'ala. May Allah Ta'ala save us from nifaaq and the evil of our deeds.