Performing acts of worship with mixed intentions

Performing acts of worship with mixed intentions related to polytheism, that being, when a person does an act of worship for the Sake of Allaah and another purpose at the same time, such as he makes ablution in the sense of worship and to cool down at the same time. Such mixed intentions is of three types. It is either to do one act of worship alongside another, a permissible act alongside an act of worship, or a prohibited act alongside an act of worship. These types are explained as follows:
1.    Doing one act of worship alongside another. This may take different forms: both acts of worship may be obligatory, both voluntary, or one obligatory alongside a voluntary one. In some cases, the act of worship becomes invalid, and in others it does not. For example, if a person intends to perform an obligatory prayer and the voluntary prayer which is preferred to do on entering the mosque at the same time, this is valid, if he intends to perform an obligatory prayer and the voluntary prayer which is prayed before or after it, at the same time, the act of worship is invalid, and neither are accepted.
2.    Doing a permissible act alongside an act of worship, such as a doctor advising a person to lose weight, and the person wished to go around the Ka’bah, ttawaaf, instead of walking in the streets and markets. His intention for ttawaaf was to be rewarded and lose weight at the same time. Such a person would be rewarded, Allaah willing, because performing ttawaaf rather than walking in the streets is opting for that which is good. The same applies if a doctor advises him to go on a diet, and the person says, ‘I will fast rather than not and be rewarded!’, he would be rewarded, Allaah willing, because performing this act of worship rather than not is better for the person. Similarly, if the Imaam lengthens the bowing in prayer so that a person entering the mosque can catch the unit of prayer, this is an example of more than one intention. This is because the Imaam prolonged the bowing for the benefit of his Muslim brother catching the unit of prayer. The scholars have no issue with this as long as he does not overburden those praying behind the Imaam, despite the fact that this was rejected by Imaam Qurttuby.
3.    Doing a prohibited act alongside an act of worship, such as sacrificing for Allaah and for something else at the same time. Such mixed intention is prohibited and, in fact, is a major form of polytheism which necessitates the sacrificed animal to be prohibited from being eaten from.
The issues of mixed intentions in acts of worship are problematic and various. Some are permissible by agreement of the scholars, some there is a difference of opinion about, and others are impermissible by agreement of the scholars. However, a person whose intention is sincere for worship without associating any other act with it at the same time, this, without doubt, has a greater reward.