This Monday, nearly 1.6 billion Muslims across the world celebrate Eid al-Adha or “the festival of sacrifice.”

Considered the holier of the two Eids, the festival earns its name from the annual sacrifice of cows and other livestock, which in turn commemorates the story of Abraham’s willingness to sacrifice his son to God.

Here are three things to know about this year’s Eid al-Adha:

1. The run-up has been accompanied by a war of words between Iran and Saudi Arabia.

Harsh exchanges of rhetoric between the religious leaders of Iran and Saudi Arabia took place during hajj, the annual Islamic pilgrimage to the holy city of Mecca, which falls just before Eid al-Adha.

Referring to a stampede last year that killed at least 750 people near Mecca, Iran’s Supreme Leader, Ayatollah Ali Khamenei, last Monday criticized Saudi Arabia’s management of the Islamic world’s holiest site, which lies within Saudi borders.

Khamenei said the Saudi ruling family “does not deserve to be in charge and manage the holy sites,” Agence France-Presse reports.

Saudi Arabia’s Grand Mufti Sheik Abdulaziz al-Sheik in turn told reporters that Iran’s leaders “are not Muslims,” according to a local report cited by al-Jazeera. “They are children of the Magi and their hostility towards Muslims is ancient,” he reportedly said, referring to the pre-Islamic Persian Zoroastrian religion.

2. The volume of trade in livestock at this time of year is enormous.

As many as a million goats were sent from Berbera port in Somaliland to Saudi Arabia this year, contributing to one of the largest trade movements of livestock in the world, al-Jazeera reports.

The trade is absolutely vital to Somaliland — a breakaway territory from Somalia that declared independence in 1991 but has since gone unrecognized. Today, almost all of the territory’s export income is derived from livestock, providing vital earnings for one of the world’s poorest places, with a youth unemployment level of around 70%.

3. This year’s Eid will be more frugal for many Muslims.

Although the Eid holidays are traditionally known for lavish spending, many Muslims around the world will celebrate more frugally this year. According to Reuters, low oil prices have caused consumers in Saudi Arabia to spend less during this year’s holiday season.

In Indonesia, the world’s most populous Muslim nation, people have reportedly been buying communal cows to sacrifice with their neighbors, owing to the country’s economy shrinking to its slowest growth in six years.

In Pakistan, where the annual per capita income is just $1,500, many families will also be pooling resources to jointly buy a sacrificial animal, the Washington Post reports.

Those who are able to spend, however, can drop by Indian e-commerce site OLX, says the Times of India, and buy goats named after Bollywood stars for up to $1,650.

Get The Brief. Sign up to receive the top stories you need to know right now. Please enter a valid email address. Sign Up Now Check the box if you do not wish to receive promotional offers via email from TIME. You can unsubscribe at any time. By signing up you are agreeing to our Terms of Use and Privacy Policy . This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply. Thank you! For your security, we've sent a confirmation email to the address you entered. Click the link to confirm your subscription and begin receiving our newsletters. If you don't get the confirmation within 10 minutes, please check your spam folder.

Contact us at letters@time.com.