true believers are those who sincerely believe in allah and his messenger and who do not leave him without permission when they are with the messenger for some common good only those who ask your permission sincerely believe in allah and his messenger. therefore when they ask your permission for a private business you may give permission to whomever you like and ask allahs forgiveness for such people allah is indeed forgiving and merciful.
إنما المؤمنون الذين آمنوا بالله ورسوله وإذا كانوا معه على أمر جامع لم يذهبوا حتى يستأذنوه إن الذين يستأذنونك أولئك الذين يؤمنون بالله ورسوله فإذا استأذنوك لبعض شأنهم فأذن لمن شئت منهم واستغفر لهم الله إن الله غفور رحيم