"And indeed, there are watchers over you," meaning: the angels who record the deeds of the servants.
﴿وَإِن عَلَيْكُم لحافظين﴾ يَعْنِي: الْمَلائِكَةَ الَّتِي تَكْتُبُ أَعْمَالَ الْعباد