What is the ruling on ghabqa in Ramadan?

This ghabqa is a feast, and feasts come under the heading of customs and traditions, which are in principle permissible.

Shaykh al-Islam Ibn Taymiyah (may Allah have mercy on him) said:

People’s activities – words and deeds – are of two types: that which they have to do in order for their faith to be sound and that which they need to do so that their worldly affairs will be sound. By examining the Islamic guidelines, we learn that the acts of worship that Allah has enjoined and that He likes cannot be proven except on the basis of religious texts.

As for people’s customs and traditions, this refers to what people are accustomed to and need with regard to the way in which they run their worldly affairs. In principle, they are not prohibited, so nothing is to be prohibited except what Allah, may He be glorified and exalted, has prohibited.

The basic principle regarding customs and traditions is that they are to be overlooked, so nothing of them is prohibited except what Allah has prohibited, otherwise we will be among those referred to in the verse (interpretation of the meaning): {Say, “Have you seen what Allah has sent down to you of provision of which you have made [some] lawful and [some] unlawful?”} [Yoonus 10:59]. Hence Allah criticized the polytheists who introduced religious practices for which Allah did not give permission, and they forbade that which He did not forbid.… This is an important and beneficial principle." (Majmoo‘ al-Fataawa 29/16-18).

However, it is very important to point out that these meals should be free of any haraam elements such as extravagance, wastefulness, boasting or wasting the nights of Ramadan in leisure and entertainment.

And Allah knows best.