PJ Num10:31 :והוית חביב עלן כבבת עיננא‏ : you were as precious to us as the pupil of our eyes
See the entire entry for bāḇā, bāḇtā n.f. pupil of the eye

PJ Num10:31 :לא כדון תשבוק יתנא ארום בגין כן‏ : please do not leave us for the following reason
See the entire entry for bḡēn/bḡīn kēn conj. therefore