We were short on money, and I didn't think I could get my son the train set he wanted for Christmas. Another mom came to my rescue.

• Courtney Ellis is a 42-year-old mom of three in Mission Viejo, California.
• She found a used train set online and agreed to buy a quarter of the set.
• When she went to collect the set, the seller gave her the entire set for no extra cost.

This as-told-to essay is based on a conversation with Courtney Ellis, author of Looking Up. It has been edited for length and clarity.

Ten years ago, my husband and I moved with our 2-year-old son from Wisconsin to California to work at a church. My husband was finishing a Ph.D., and our only source of income was a pastoral position at the church, which we split between the two of us.

We were eating through our savings just to make ends meet, living in a tiny condo, and hoping that in time, we'd both be able to take on more hours at the church.

Our first Christmas in California, I wanted to make our son's Christmas special despite the stress of money and budgeting. Retrospectively, I can now see he would have been just as happy with a cardboard box, but at the time, as his mom, I wanted to be able to give him the world.

I couldn't afford the train set

I'd recently found a train table at a garage sale for $5. Whoever had it previously had colored all over it with crayons, hence the price.

Knowing I needed trains to accompany the table, I looked online and found a beautiful Thomas the Tank Engine set just a mile away. It had all the character trains and accessories. When I saw the price, I knew I couldn't afford the full set, so I asked the seller if I could just buy a quarter of it. I knew she might say no — that she might want to sell it as a package — but I asked, and she agreed.

She asked what part of the set I wanted, and I requested enough tracks to make a circle and a few trains.

I was completely thrilled that we would be able to give him a gift I knew he would love on Christmas morning.

When my son fell asleep, I left him with my husband, and I drove my 20-year-old car a mile to get the train set, expecting I might arrive at a huge house. But I arrived at a small condo, much like my own. I assumed she was probably selling this train track to pay for her own kids' Christmas presents.

When she opened the door, she held out a clear Ziploc bag of train tracks and trains. I thanked her and explained that we had just moved to the area. I was so thankful she was willing to sell me just a portion of the track — it was exactly what I had been looking for.

She gave me the entire train set

In that moment, we connected as frazzled, busy moms.

I got out the money to pay her, and she told me to wait, leaving me waiting at the front door with my money and train set in hand. I thought maybe she had forgotten one of the pieces.

She came back with three more bags of train sets. I was afraid there was a misunderstanding but I didn't want to say that I couldn't afford the rest of the set.

"Oh, I think we had just agreed on the one part of the set," I told her.

"I know," she responded. "Merry Christmas."

She handed me the bags, took my money, and closed the door behind her, leaving me on the front steps, trying to compose myself after experiencing such unexpected kindness.

I still cry thinking about that moment

I still tear up thinking about that moment. We were so financially strapped and really stressed about our budget, and she treated me with tenderness. It was life-changing, in a small way, and has stayed with me all these years later.

Recently, one of my sons told me a neighbor boy really liked these big trucks we have.

"I think I'm ready to say goodbye to my big trucks," he told me. "Can we take them over to the neighbor's house?"

Maybe at one time, I would have thought I could have gotten money for the trucks, but then I think back to how that woman gave me that extra train track. Since then, we have always tried to give as we have been given to, to pass on the gift of generosity, even in small ways. We decided to give as we have been given.

When I wrote about the train tracks on Threads, so many people commented about their own personal experiences of kindness. When we perform acts of generosity or share about how someone has been generous to us, I think it helps us and others begin to develop eyes to look for all the light around us in the middle of what can feel like darkness.