[16].Surah An-Nahl [The Bees] : Ayat 115

Ayat 115. He has forbidden you only Al-Maytatah (meat of a dead animal), blood, the flesh of swine, and any animal which is slaughtered as a sacrifice for others than Allah (or has been slaughtered for idols etc. or on which Allah's Name has not been mentioned while slaughtering). But if one is forced by necessity, without willful disobedience, and not transgressing, then, Allah is Oft-Forgiving, Most Merciful. . 

Hazrat Abu Hurairah (May Allah be pleased with him) said: The Messenger of Allah [SAWW](PBUH) said, "O people! Allah is Pure and, therefore, accepts only that which is pure. Allah has commanded the believers as He has commanded His Messengers by saying: `O Messengers! Eat of the good things, and do good deeds.' (23:51) And He said: `O you who believe (in the Oneness of Allah - Islamic Monotheism)! Eat of the lawful things that We have provided you...''' (2:172). Then he (PBUH) made a mention of the person who travels for a long period of time, his hair are dishevelled and covered with dust. He lifts his hand towards the sky and thus makes the supplication: `My Rubb! My Rubb!' But his food is unlawful, his drink is unlawful, his clothes are unlawful and his nourishment is unlawful, how can, then his supplication be accepted?''  

[Muslim Book 08, Chapter 18, Hadith # 2214]. 

Lesson : as mentioned above in Surah An-Nahl Ayat 115. But if one is forced by necessity, without willful disobedience, and not transgressing, then, Allah is Oft-Forgiving, Most Merciful. For the grant of prayer, honest earning is essential. Allah accepts charity only if it has been earned in an honest way. Moreover, before any pious action, honest earning for living is essential; otherwise good actions will also go waste.