An ancient book of national songs, which most likely contained both religious and secular songs describing great events in the history of the nation. In the OT there are two quotations from this book
Joshua spoke to Jehovah the day when Jehovah delivered the Amorites to the children of Israel. He said in sight of Israel: Sun, stand still upon Gibeon; and Moon, stand still in the valley of Ajalon. The sun stood still, and the moon stood still, until the people had avenged themselves upon their enemies. Is this not written in the book of Jasher? So the sun stood still in the midst of heaven, and did not go down for a whole day.
Your beauty, O Israel, is slain on your high places! How the mighty have fallen! Do not tell the news in Gath. Do not announce the victory in the streets of Ashkelon. The daughters of the Philistines will be glad. The daughters of godless men will celebrate. read more. Let no rain or dew fall on the mountains of Gilboa. Let its fields be barren! For the shields of the mighty lie there in disgrace. The shield of Saul is no longer polished with oil. Jonathan's bow was deadly. The sword of Saul was without mercy. He struck down the mighty and killed the enemy. It was easy to love Saul and Jonathan. Together in life, together in death, they were faster than eagles and stronger than lions. Daughters of Israel, weep over Saul. He clothed you in scarlet with luxury. The brave soldiers have fallen. They were killed in battle. Jonathan lies dead in the hills. I grieve for you, my brother Jonathan. You were dear to me! How wonderful was your love for me. It was better than the love of women. The mighty have fallen, their weapons abandoned and useless.
Solomon prayed: Jehovah, you have placed the sun in the sky, yet you have chosen to live in clouds and darkness.