Eligible tourists may stay in Israel for up to 90 days per visit. The limit applies separately to each continuous stay. ETA-IL is required for travelers from visa-exempt countries and may be valid for multiple entries for up to 2 years, but each individual stay is limited to up to 90 days or less as authorized on entry.
https://embassies.gov.il/singapore/en/services/foreign-citizens/application-eta-il-approval