Rule 308...
Rule 308: It is permissible to sit down to rest in the course of a tawaaf but it must not be prolonged so much that the sequence as generally accepted be broken for in that event the tawaaf becomes invalid and has to be performed again.
IRREGULARITIES IN TAWAAF Rule 309: If a pilgrim interrupts a tawaaf in order to obtain the benefit of praying at the earliest time or join congregational prayers or perform the recommended prayers, then he must complete the tawaaf from where he interrupted it after completing his prayers. As a matter of caution, he should repeat the tawaaf after completing it if the interruption was in the course of an obligatory tawaaf and occurred before completing the fourth round.
Rule 310: If during a tawaaf an omission is made by inadvertence and the pilgrim becomes conscious of the impropriety before the sequence of continuity is broken and he has not left the area of tawaaf, he should complete it and it will be valid.However, if he becomes conscious of it after the sequence is broken, then if he had forgotten to perform one round or two or three rounds, he should perform it or them, and the tawaaf will be valid.
If he cannot perform it personally even though he remembers after returning to his home, he may appoint an agent to perform it on his behalf. If he had forgotten more than three rounds, he should return and perform the missed ones but it is better that having done so, he should perform another full tawaaf.
ADDITIONS IN TAWAAF There are five kinds to be considered: If there is no intention to make any additions as part of the tawaaf being performed or another tawaaf, for example that it was intended to make one more round assuming that it was recommended to do so, any addition made does not invalidate the tawaaf.
If at the commencement or in the course of a tawaaf an intention is formed to make an addition as part of the tawaaf being performed, it is undoubtedly invalid and has to be performed again. If after completion of the tawaaf, any addition made is considered part of the tawaaf performed, then it is clear that the tawaaf becomes invalid.
If the addition is intended to be part of another tawaaf, the other tawaaf will need to be completed but it will not be valid as two tawaafs will have been joined except if both the tawaafs are not obligatory ones, but it is discouraged to join two tawaafs.