Praise be to Allah.
The hadeeth which is narrated from the Prophet (peace and blessings of Allaah be upon him) concerning istikhaarah is comprehensive and includes all matters which may be of concern to people and which they may not know whether it is better to do it or not. So they may pray istikhaarah and ask Allaah for guidance. But that does not include things that are enjoined on a man, because doing things that are required of him is good and there is no room for hesitation about that. Based on this, if Hajj is obligatory for a person and the conditions of it being obligatory have been fulfilled, then he should go for Hajj without praying istikhaarah. By the same token, if the adhaan is given for Zuhr prayer, for example, it is obligatory for him to pray without praying istikhaarah; and if jihad becomes obligatory for him as an individual obligation (fard ‘ayn), he has to engage in jihad without praying istikhaarah.
But if it is something that is allowed in Islam but is not obligatory, then he may pray istikhaarah concerning it. Some permissible things are better than others. A man may want to go and perform a voluntary ‘Umrah, or a voluntary Hajj, but he does not know whether it is better for him to go for Hajj or to stay in his country to call others to Allaah and teach the Muslims and take care of his family. So he should pray istikhaarah and ask Allaah for guidance, not because he has any doubts about the virtues of ‘Umrah, but because he is not sure whether it is better to go for ‘Umrah or stay in his country. This is something understandable and one can pray istikhaarah about this.
Whoever studies the hadeeth about istikhaarah and the teachings of the Prophet (peace and blessings of Allaah be upon him) will realize that it has only been prescribed in cases where one may be hesitant. In cases where there is no hesitation or uncertainty, there is no need for istikhaarah. As I have stated above, in the case of obligatory duties there is no room for hesitation or doubt about doing them, because it is obligatory for the one who meets the conditions of their being obligatory to do them. End quote.