It was not long before
Temporal Interval & Duration
ما لبِث / لم يلبَثْ (+ الفاعل) ... + (أن / حتى) + ماض نادراً: لا يلبَثُ / لن يلبَثَ (+ الفاعل) ... + (أن / حتى) + مضارع منصوب
Focuses on the shortness of the interval. A short, measurable gap of time passes, then B happens. لبث may also take أنْ when introducing the event directly. When a second event/clause is introduced, حتّى (never فـ ) is used for as the linker