Laudator Temporis Acti

Zenobius 6.13 (tr. W.G. Arnott on Menander, Leukadia, fragment 8):

'The pebbles in the quiver'. Phylarchus says that when Scythians were going to bed, they brought their quiver, and if they had spent that day free from pain or grief, they dropped into the quiver a white pebble, but if the day had been troublesome, a black one. So at the time of their deaths the quivers were brought out and the pebbles counted. If the white ones were found to be more numerous, they called the man who had departed happy.

τὰς ἐν τῇ φαρέτρᾳ ψηφῖδας· Φύλαρχος φησι (FGrH 81 F 83, 2A p. 188 Jacoby) τοὺς Σκύθας μέλλοντας καθεύδειν ἄγειν τὴν φαρέτραν, καὶ εἰ μὲν ἀλύπως τύχοιεν τὴν ἡμέραν ἐκείνην διαγαγόντες, καθιέναι εἰς τὴν φαρέτραν ψηφῖδαν λευκήν· εἰ δὲ ὀχληρῶς, μέλαιναν. ἐπὶ τοίνυν τῶν ἀποθνῃσκόντων ἐκφέρειν τὰς φαρέτρας καὶ ἀριθμεῖν τὰς ψήφους· καὶ εἰ εὑρεθείησαν πλείους αἱ λευκαί, εὐδαιμονίζειν τὸν ἀπογενόμενον.

Much the same appears in the Suda, s.vv. Λευκὴ ἡμέρα and Τῶν εἰς τὴν φαρέτραν.