Possible Clues:

• Biblical grain measure
• Hebrew measure
• Post-Passover period
• Passover-to-Shavuot period
• Seven-week period in Judaism that begins during Passover
• 49-day liturgical season
• One-tenth of an ephah
• Traditional Passover barley offering
• About half a gallon - could be more
• 1/10th of an ephah