Andtheytarrieduntilafternoon - Merely that they might avoid the heat of the day, which would have been very inconvenient in travelling.
SDA Bible Commentary (limited)
Volume 1-7
8. Tarried. Again the father-in-law persuaded them to delay their departure until he could prepare another meal. Evidently it too was a large feast which the father-in-law did not hurry to prepare and during which there was much leisurely talk.