William Burkitt on 1 Peter 4:9

As a principal act and eminent exercise of charity, the apostle advises to use hospitality to their poor brethern, without grudging or murmuring at the charge: hospitality is a necessary, a commendable, and a commanded, duty; St. Paul requires, that we be given to hospitality. Rom 12:13

Observe farther, the apostle doth not barely say, use hospitality, but use it one to another: it is a mutual duty; whence it appears, that though hospitality towards the poor be a commanded duty, yet hospitality among the rich is no sin, but a duty likewise, to give reciprocal entertainments; for though our Saviour says, Luke 14:12. When thou makest a dinner, or a supper, call not thy friends and rich neighbours; the prohibition is not absolute, he doth not forbid the inviting of the rich, but chargeth us not to forget the poor: we may treat both, if we have enough for both; but if not, what we have to spare must be for them that have nothing, not for them that have enough already, for we must prefer works of pious charity before acts of civil courtesy: Use hospitality one to another without grudging.