Is it considered wrong for a husband to delay his prayer to help his wife, who suffers from obsessive-compulsive disorder, perform ablution and prayer, even if this leads to him performing it only a few minutes before the entry of the next prayer's time, knowing that his failure to assist her might cause her to miss the prayer or spend a long time in purification?

It is permissible to delay the prayer until near the end of its time without sin, as long as it does not go out of its time. There is no harm in performing the prayer in congregation with one's wife at home if she is in need of it. The virtue of congregational prayer in the mosque can be attained by praying there at the beginning of the time, then returning to help one's wife. The wife should continue to ward off whispers (waswas) by seeking Allah's help and relying on Him.