This quote by Sophocles is a caution against accepting gifts from enemies. It recommends that these gifts are not authentic and should not be trusted. The quote suggests that enemies may offer gifts as a method to control or trick someone. It is a pointer that enemies may have ulterior intentions and that their presents need to not be trusted.
The quote likewise suggests that accepting presents from enemies can be hazardous and can cause damage. It is a tip that enemies may be attempting to acquire something from the recipient, which the recipient should watch out for any presents they receive. The quote is an alerting to be careful and to think twice prior to accepting gifts from opponents. It is a reminder that opponents' presents are not authentic and can do more damage than good.