Shaikh `Abdur-Rahmaan ibn Naasir as-Sa`dee -rahimahullaah- was asked about a group of travellers who combine the Prayers, or shorten them, and there is amongst them someone who does not hold it to be correct, should he follow them upon that?
QUESTION:
“If a group hold combining, or those who wish to shorten do so, and there are along with them those who do not believe that to be permissible, then is it allowed for him to go along with them in their combining or their shortening? And will it be the same as if the imaam had left something which one person praying behind him held to be a condition or a pillar?”
ANSWER:
“This is not the same as following one who leaves a condition or a pillar which the follower believes to be a condition or a pillar, because in that situation the imaam is the one who is leaving something which the follower believes to be something binding, so this will not harm the follower’s praying behind him, because the follower has not left that condition which the imaam left, nor that pillar which he left.
As for going along with them for one who does not hold combining for those who combine; and who does not hold shortening for those who shorten, then this will not be correct from him, since he himself will be doing that which he holds to be not permissible; and the difference between the two issues is clear when it is carefully considered.”
[‘al-Majmoo`atul-Kaamilah limu.allafaatish - Shaikh `Abdir-Rahmaan ibn Naasir as- Sa`dee’: 16/125]
[Translated by Aboo Talhah Daawood ibn Ronald Burbank rahimahullaah]
Source: www.alitisaambissunnah.wordpress.com