Erasmus, Adagia 25:

Diogenianus thinks that this has the same force: Κινῶ τὸν ἀφ᾽ ἱερᾶς, that is, I move the die from the sacred line. This is said of those who are about to undertake the most extreme measures. Julius Pollux, laying this out in his ninth book, says that the adage derives from a certain kind of dice game, and that the game was of this sort: for each of the players, there were five little stones placed upon the same number of lines, from which Sophocles said πεσσὰ πεντέγραμμα, that is, the dice of the five lines. Between those lines (five on each side) there was one in the middle, which they called sacred. Whoever moved the die past that point was said to have moved the die of the sacred line. But that never happened except when the game demanded it, when the player needed to flee to their last resort.

Plato employs this adage in the fifth book of his Laws: Καθάπερ πεττῶν ἀφ᾽ ἱεροῦ, that is, As if from the sacred die. Plutarch, in his book, Whether the Republic Should Be Run by an Old Man, writes: Τελευταίαν ὥσπερ τὴν ἀφ᾽ ἱερᾶς ἐπάγουσιν ἡμῖν τὸ γῆρας, that is, they charge us with senility as if moving the die from the sacred line, which is to say, this is the gravest charge. Plutarch also says in his Comparison of Terrestrial and Marine Things: Φέρε κινήσαντες τὴν ἀφ᾽ ἱερᾶς βραχέα περὶ θειότητος αὐτῶν καὶ μαντικῆς εἴπωμεν, that is, Come on, let’s move the die from the sacred line and talk a little about their divinity and divination. And again he writes in his essay Against Colotes: Εὐθὺς οὖν τὸν ἀφ᾽ ἱερᾶς κεκίνηκεν ὁ Κολώτης, that is, Colotes straightaway moved the die from the sacred line, which is to say that he immediately proceeded to the most extreme measure, so that he could attack the judgment of Apollo concerning Socrates. Plutarch also writes in the life of Martius Coriolanus, about the Roman people being disturbed by Coriolanus’ threats, Ἄρα τὴν ἀφ᾽ ἱερᾶς ἀφῆκεν, that is, he tossed away the die taken from the sacred line, because the Romans, with all hope of success having been lost, fleed to the religion of the gods and sent priests, temple custodians, initiators, and augurs to supplicate the gods. Theocritus alludes to this in his Bucolics: Καὶ τὸν ἀπὸ γραμμᾶς κινεῖ λίθον, that is, and he moves the stone from the little line, which I have mentioned elsewhere.

MOVEBO TALVM A SACRA LINEA

Idem pollere putat Diogenianus: Κινῶ τὸν ἀφ᾽ ἱερᾶς, id est Sacrae lineae talum moueo. De iis, qui extrema parant experiri. Id Iulius Pollux libro nono exponens ait a ludo quopiam tesserarum natum esse adagium. Lusum autem fuisse huiusmodi, vt vtrique ludentium essent calculi quinque totidem impositi lineis; vnde et Sophocles dixerit πεσσὰ πεντέγραμμα, id est tesserae quinque linearum. Inter eas lineas, vtrinque quinas, vnam fuisse mediam, quam sacram vocabant; vnde qui talum mouisset, is sacrae lineae calculum mouere dicebatur. Id vero non fiebat, nisi cum res posceret, vt ludens ad extrema confugeret auxilia. Vsurpat hoc adagium Plato libro De legibus quinto: Καθάπερ πεττῶν ἀφ᾽ ἱεροῦ, id est Tanquam a sacra tessera. Plutarchus in libro, qui inscribitur An seni sit gerenda respublica: Τελευταίαν ὥσπερ τὴν ἀφ᾽ ἱερᾶς ἐπάγουσιν ἡμῖν τὸ γῆρας, id est Postremam nobis tanquam a sacra linea senectam allegant, hoc est veluti causam grauissimam. Idem commentario De comparatione terrestrium ac marinorum: Φέρε κινήσαντες τὴν ἀφ᾽ ἱερᾶς βραχέα περὶ θειότητος αὐτῶν καὶ μαντικῆς εἴπωμεν, id est Age moto talo a sacra linea paucis de diuinitate eorum et diuinatione dicamus. Rursum idem Aduersus Colotam Epicureum: Εὐθὺς οὖν τὸν ἀφ᾽ ἱερᾶς κεκίνηκεν ὁ Κολώτης, id est Protinus igitur talum a sacra mouit Colotes, hoc est statim id quod est grauissimum aggressus est, vt impugnaret Apollinis de Socrate iudicium. Idem in vita Martii Coriolanide ciuitate Romana ob Coriolani minas perturbata: Ἄρα τὴν ἀφ᾽ ἱερᾶς ἀφῆκεν, id est Sublatam a sacra linea tesseram misit. Desperatis enim rebus ad deorum religionem confugiebat supplicatum missis sacrificis, aedituis, initiatoribus, auguribus etc. Huc allusit et Theocritus in Bucoliastis: Καὶ τὸν ἀπὸ γραμμᾶς κινεῖ λίθον, id est Atque a lineola lapidem mouet, de quo nobis et alias facta mentio.